Exposure of nuclear-grade activated carbons to accident scenarios

This paper examines the effects of radiation on activated carbon adsorbers used for the removal of radioactive emissions from nuclear power systems. The concentration of radioactive iodine, 131I, can increase manyfold above background levels during a reactor accident, thus increasing the rates of chemical reactions with both the base carbon and the impregnated chemicals. Accident scenarios are postulated and subsequent carbon behavior is studied. A number of service carbons were exposed to an accumulated level of 109 rads (32 hours) in a LINAC. The penetrations of methyliodide-131 were determined using the Ge-Li detector. The recovery of carbon efficiency appears to increase with the quantity of contaminants directed to the carbon adsorber during service. It is concluded that any process that would maintain isotope exchange is greatly to be desired since the goal in nuclear applications is the retention of the radioactive iodine species by the carbon bed